The Tonkin Free School (Vietnamese: Đông Kinh Nghĩa Thục, 東京義塾) was a short-lived but historically significant educational institution in Hanoi that aimed to reform Vietnamese society under French colonialism during the beginning of the 20th century.
The school was founded in March 1907, run by Lương Văn Can with the participation of many nationalists, including Phan Bội Châu and Phan Chu Trinh. It stemmed from the movement of the same name, which aimed to modernize Vietnamese society by abandoning Confucianism and adopting new ideas from the West and Japan. In particular, it promoted the Vietnamese alphabet script for writing Vietnamese in place of classical Chinese by publishing educational materials and newspapers using this script, as a new vehicle of instruction. The schools offered free courses to anyone who wanted to learn about the modern spirit. The teachers at the school at 59 Hàng Đàn included Phạm Duy Tốn.
The school operated legally for several months before the French authorities closed it down in November. In March 1908, a tax revolt in Annam and an attempted poisoning of French soldiers in Hanoi were blamed on the leaders of the school by the French. Subsequently, all the leaders were arrested and the school's publications were suppressed.